1. Field of the Invention
The present invention relates to liquid-ejection testing methods, liquid-ejection testing devices, and computer-readable media.
2. Description of the Related Art
<No. 1>
Inkjet printers are known as printing apparatuses for carrying out printing by ejecting ink onto various media such as paper, cloth, and film. Inkjet printers perform color printing by ejecting ink of various colors such as cyan (C), magenta (M), yellow (Y), and black (K) to form dots on the medium. Ink is ejected using nozzles.
However, in these inkjet printers, clogging can occur in the nozzles due to adherence of the ink for example, and the ink may not be ejected properly. When ink cannot be ejected properly from the nozzles, dots cannot be formed appropriately on the medium, and this results in the trouble that an image will not be printed clearly.
Thus, various methods for testing whether or not ink is properly ejected have been conventionally proposed. As one method, a testing method for optically detecting ink ejected from the nozzles has been proposed (see JP 2000-233520A). In this testing method, a photodiode detects whether or not a beam emitted from an LED is blocked by ink ejected from a nozzle, so that whether or not ink is ejected from the nozzle is checked.
<Problem 1>
However, this testing method has the problems as follows. It is very difficult to positionally align a beam emitted from an LED and ink ejected from a nozzle. When ink is ejected from the nozzle in a curve, it is impossible to detect ink ejection, and thus it may be impossible to accurately detect whether ink is being ejected or not.
<Problem 2>
Furthermore, in the ejection test that has been conventionally carried out, a method in which the ejection test is performed row by row on a plurality of nozzle rows arranged in the head while moving the head relative to the testing device has been employed. In this method for performing the ejection test one by one on the rows, it is necessary to move the head each time the test target is switched from one nozzle row to another nozzle row. Thus, it takes considerable time to perform the ejection test because of the time required for moving the head and the time for positionally aligning the nozzle rows arranged in the head and the testing device. When such an ejection test is performed, it is preferable to make the movement of the head small to the extent possible.